Im going to look at a rear from an 88 iroc this weekend and need to tell i think if you turn one side and the other turns the same way its posi.or if you hold the opposite side while turning and it doesnt turn its not...ive been told too many things and need a deffinate way to tell...thanks
Oh and the rear is out of the car

 

HAve one peron to hold one side, and you turn the other. if they feel you turnin it, then it's a posi.

 

The only way to tell is to pull the cover. Don't believe anthing anybody else tells you, they are all olds wive's tales.

 

Yeah, its best to pull the cover. GENERALY if its a posi then both axles will spin the same direction when you spin one side by hand. But, someone could have welded the spider gears or it could have a spool...........so its best to pull the cover. If the guy is honest and really want to sell it then he will pull it for you or at least let you pull it off and take a look inside.

 

it depends...there is no definitive anser...but there R a few things to look for, first all posi's has a little metal tab sticking out from the carrier saying "limited slip diff fluid only", but these may or may not be still on there, second if the posi still works, jack up both tires of the rear end, and put the car in park, or in gear(on a manual...the idea is to keep the driveshaft from turning)...try to turn the one weel....if it is difficult or inpossable to turn it the posi still works, if it turns easally and the other tire turns the OPPISID direction it either has a bad posi unit, or none at all, third you can pull the cover and see if thre are springs in the carrier if there are it is a posi.